Perineural scar formation, also known as peridural fibrosis, is a common occurrence after lumbar discectomy surgery. Peridural fibrosis can cause compression or tethering of the nerve root and has been implicated in recurrent radicular and/or low back pain after a lumbar discectomy. Fibrosis may be the underlying cause in as many as a quarter of all failed back surgery syndrome cases. Reoperation with the intention of excising this fibrous tissue often produces a poor surgical result and further scarring. Furthermore, a large variety of materials have been implanted onto the dura in animal models with the goal of preventing perineural fibrosis with only modest success. Low dose radiation has long been known to inhibit fibroblast and osteoblast activity. Perioperative radiation therapy has been demonstrated to be a useful method to prevent both keloid and heterotopic bone formation in human trials. Radiation has not previously been studied as a means to inhibit peridural fibrosis. Our previous studies investigating in both rat and dog models showed a significant reduction in peridural fibrosis after laminectomy using low dose external beam radiation (700 cGy) given 24 hours prior to surgery. Based on these preliminary data, we will test the hypotheses that (1) preoperative low dose external beam radiation given 24 hours prior to surgery will decrease the amount of peridural fibrosis in humans, and (2) this reduction in peridural fibrosis will lead to an improvement in patient outcome. For this study, patients will be enrolled in a randomized double-blinded controlled clinical investigation either to preoperative radiation (treatment group) or no preoperative radiation (control group) prior to surgery. Patients will be followed at 1, 3, 6, and 12 months with self- report instruments of function, measures of impairment, and magnetic resonance imaging. As more than 10,000 patients per year in the United States have failed back surgery syndrome thought secondary to peridural fibrosis, this novel treatment strategy would be efficacious to a large number of patients with this disease process.